This discrete MOSFET stepper motor driver enables control of one bipolar stepper motor. It supports a wide 8 V to 50 V operating voltage range and can deliver up to 4 A continuous per phase without a heat sink or forced air flow (6 A max with sufficient additional cooling). The SPI interface allows configuration of the current limiting, step mode (9 step modes from full-step through 1/256-step), decay mode, and stall detection. The driver also provides back-EMF feedback that can be used for more advanced control and stall detection algorithms. Additional features include reverse-voltage, under-voltage, and over-current protection.

The Pololu High-Power Stepper Motor Driver 36v4 combines the DRV8711 stepper motor driver IC from Texas Instruments with external MOSFETs to enable control of large bipolar stepper motors at operating voltages from 8 V to 50 V. The DRV8711 has many configurable settings, so please see the DRV8711 datasheet for a detailed explanation of its features and how to use them (we also have an Arduino library that simplifies getting started by providing basic functions for configuring and operating the driver).

The driver’s power performance is a function of the external dual H-bridges, which allow the driver to deliver continuous currents up to 4 A per phase without any additional cooling such as heat sinks or forced air flow. (With sufficient additional cooling, the driver can support currents up to around 6 A per phase; see the Power dissipation considerations section below for more information, including important information about using this product safely.)

Key features

• Wide 8 V to 50 V operating voltage range
• High-power: can deliver up to 4 A continuous per phase without extra cooling (6 A max with sufficient additional cooling)
• Highly configurable through SPI interface
• Optional STEP/DIR control pins (stepping can also be controlled through SPI interface alone)
• Nine different step resolutions down to 256 microsteps: full-step, half-step, 1/4-step, 1/8-step, 1/16-step, 1/32-step, 1/64-step, 1/128-step, and 1/256-step
• Adjustable current control lets you set the maximum current output, enabling the use of voltages above your stepper motor’s rated voltage to achieve higher step rates
• Adaptive blanking time, adjustable decay times, and various current decay modes enable the creation of ultra-smooth motion profiles through the SPI interface
• Optional STALL output enables stall detection when microstepping
• Optional BEMF output enables more advanced control and stall detection algorithms based on the back EMF of the stepper motor
• Driver supports alternate operating mode for controlling two brushed DC motors with PWM inputs instead of one bipolar stepper motor with STEP/DIR inputs
• Inputs compatible with 1.8 V, 3.3 V, and 5 V logic
• Digital outputs are all open drain with pull-ups to externally supplied IOREF voltage for use with non-5V systems (IOREF can be connected to neighboring 5V OUT pin for use with 5V systems)
• Under-voltage lockout, over-current protection, short circuit protection, and reverse-voltage protection (up to 40 V)
• Arduino library and example sketches are available that provide basic functions for configuring and operating the driver

As an alternative to this stepper motor driver, our Tic 36v4 USB Multi-Interface High-Power Stepper Motor Controller has similar power characteristics and offers high-level interfaces (USB, TTL serial, I²C, analog voltage, quadrature encoder, and RC hobby servo pulses) that make it easier to use for some applications. The Tic’s configuration software allows you to change many of the driver’s settings over USB, eliminating the need to directly use SPI to configure the DRV8711.

19 September 2019 update: We are now shipping a slight revision (md38b) with improved noise and fault tolerance at high input voltages and high current limits.

Included hardware

This product ships with all surface-mount components installed as shown in the product picture. However, soldering is required for assembly of the included through-hole parts. The following through-hole parts are included:

• Two 1×12-pin breakaway 0.1″ male header
• Three 2-pin, 3.5 mm terminal blocks (for board power and motor outputs)
• One 0.1″ shorting block (for optionally connecting IOREF to neighboring V5 pin when using this driver in 5 V systems)

The 0.1″ male headers can be broken or cut into smaller pieces as desired and soldered into the smaller through-holes. These headers are compatible with solderless breadboards, 0.1″ female connectors, and our premium and pre-crimped jumper wires. The terminal blocks can be soldered into the larger holes to allow for convenient temporary connections of unterminated power and motor wires (see our short video on terminal block installation). You can also solder your motor leads and other connections directly to the board for the most compact installation.

Using the driver

Pinout

For more information about these pins, please refer to the DRV8711 datasheet.

Dimensions

General specifications

Identifying markings

Notes:

1

Without included optional headers or terminal blocks.

2

Without a heat sink or forced air flow.

3

With sufficient additional cooling. This limitation comes from the 30 mΩ current sense resistors, which are rated for 1 W.

4

To -40 V. Connecting supplies over 40 V in reverse can damage the device.